A proposed vehicle jack has a base plate of steel, on which the jack cylinder and its concentric reservoir are welded. Furthermore this known embodiment has a valve housing connected to the reservoir or the jack cylinder by means of a passage passing through the base plate and being screwed on to the base plate. The pump cylinder is attached on the upper side of the valve housing and, on the inside of the valve housing, there are provided the two nonreturn valves required for the operation of the jack as well as a manually operable blocking member for relieving the jack cylinder. This vehicle jack has the disadvantage that the production of the separate valve housing considerably increases the manufacturing costs. Also, due to the valve housing, the total weight of the jack is increased, which means a considerable disadvantage in the case of jacks which are intended for passenger vehicles.
Furthermore, a jack has been proposed in which the base plate is formed by a cast piece, and in which nonreturn valves and a relief blocking member are provided. Although the nonreturn valves are provided in the cast piece, which has no separate valve housing, almost no material and weight can be saved because the cast piece has an attachment for receiving the relief blocking member in place of the valve housing.